Genetic diversity and a population structure analysis of accessions in the Chinese cowpea Vigna unguiculata (L.) Walp. germplasm collection

摘要

Cowpea (Vigna unguiculata) is an important legume crop with diverse uses. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, a total of 200 genic and 100 genomic simple sequence repeat (SSR) markers were developed from cowpea unigene and genome sequences, respectively. Among them, 27 genic and 27 genomic SSR markers were polymorphic and were used for assessment of genetic diversity and population structure in 105 selected cowpea accessions. A total of 155 alleles and 2.9 alleles per marker were identified, and the average polymorphic information content (PIC) value was 0.3615. The average PIC of genomic SSRs (0.3996) was higher than that of genic SSRs (0.3235), and most of the polymorphic genomic SSRs were composed of di- and trinucleotide repeats (51.9% and 37.0% of all loci, respectively).